Rust preventing composition



Patented Dec. 6, 1949 BUST PREVENTING COMPOSITION John D. Gerber, Cranford, N. 3., aslignor to Standard Oil Development ration of Delaware Company, a com- No Drawing. Application mm 1:, 1947, Serial No. 719,225

5 Clalms. (01. 260-383) This invention relates to a rust preventing composition and more particularly to an oil type coating composition which has the properties of adhering to metal and preventing rust in the presence of moisture.-

It is well known that mineral oils may be used to some extent for preventing the rusting of steel and various ferrous metal products. It is also known that the efllcacy of mineral oil for rust preventing purposes may be greatly improved by incorporating therein various metallo-organic compositions, such as the oil soluble petroleum sulfonates.

Under conditions of high humidity, especially in tropical or semi-tropical climates, considerable diiiiculty has been encountered in preventing rust, particularly in damp areas or areas near the ocean, and under any conditions where both humidity and temperature are high. Diiliculty has also been encountered in securing proper adhesion of the rust preventing composition, or slushing oil, to metal, especially to smooth machin d surfaces of steel, iron, and various ferrous metals.

It has now been found that the adhesive propert es and the rust inhibiting characteristics of prior art compositions, for example, mineral oil solutions of petroleum sulfonates, may be reatly improved by the incorporation of a relatively small amount of a resinous type polymer obtained from unsaturated hydrocarbons; Various resinous polymers are useful but in particular, the fl n -oiefln copolvmer resi s are especially su table for this purpose. B their use exc llent metal ad esion is obtained for slushina oils and the durability and effect veness of rustprooflng treatments are very materially improved.

A specific preferred resinous material for purposes of the present invention is a butadiene and diisobutylene copolymer which is produced by the catalytic copolymerization of these raw materials at a low temperature, for example, C. Although this particular resin ap ears to have excellent properties and is specifically preferred for this purpose, the invention also contemplates the use of analogous copolymers. However, the diene-olefin copolymers such as those which may be obtained by copolymerizing butadiene, isoprene, dimethyl butadiene, cyclo-pent'adiene, divinyl benzene, and the like, with suitable olefins or other unsaturated compounds, such as styrene, isobutylene, propylene, propylene polymers, octadecene, maleic anhydride, methyl acrylate, diethyl fumarate, vinyl acetate, vinyl chloride, and other analogous vinyl compounds are preferred.

In general, the copolymers of a major proportion of butadiene with a minor proportion of diisobutylene are preferred, but as indicated above, other copolymers of dienes and monooleilns and related unsaturated materials are useful. The simple polymers, such as polybutadiene and other polydiene oils or resins made by the sodium or emulsion technique may be used, but are not considered as satisfactory as the specific butadiene diisobutylene polymers described below.

In addition to the resinous or oily type polymers and copolymers described above, other conventional additives may be incorporated in slushing oils if desired, such as viscosity index improvers, antioxidants, pour point depressors, tackiness and anti-tackiness agents, etc. An important feature of the present invention, however, is the use of a polymer or copolymer in such proportions and having such characteristics as to improve the adhesion of the slushing oil composition to the metal surface for which it is intended to provide protection.

In general, it is preferred to employ the resinous or oil type polymers or copolymers, or mixtures thereof, as referred to above, in combination with metallo-organic type rust inhibitors. Suitable compositions of preferred type may comprise from 80 to 98% by weight of mineral oil of appropriate grade. The mineral oil may be preferably of about lubricating grade, although its viscosity may be varied within rather wide limits, for example, from 20 to 300 S. S. U. at 210 F. The oil obviously may contain other materials, such as fatty oils, fatty acids, and the like. To a suitable mlneral oil there is added from 0.1 to 10% by weight, based on the total composition, preferably 0.5 to 5% of a suitable metallo-organic rust inhibitor, preferably an oil soluble sulfonate, such as the calcium or sodium sulfonates obtained by treatment of petroleum sulfonic acids with appropriate metal hydroxides. Obviously, the oil soluble sulfonates of various metals, such as the alkalis, and alkaline earth metals, and others may 3 be employed. Sodium sulfonate is usually preferred because of its low cost.

The preferred composition further comprises a quantity of the resinous or oily type polymer or copolymer referred to above to promote adhesion to metals. Such materials will be used in appropriate proportions to secure the desired qualities of tackiness or adhesiveness in the slushing composition. Proportions of the polymer or copolymer may vary from as little as 0.5% to as much as 15% by weight or more, based on the total composition.

The invention may be further illustrated by the following specific examples, it being understood that the various other compositions and ingredients referred to hereinabove may be substituted in various proportions, depending upon the particular use and degree of rustprooflng required.

Example 1 A solution of 4 parts of an oil soluble petroleum sulfonate of sodium and 6 parts of a resinous copolymer produced by the polymerization of 55 parts of butadiene and 45 parts of diisobutylene at a polymerization temperature of about 20 C. in 90 parts of low viscosity white mineral oil was prepared by heating the agitated mixture at a temperature of 75 C. for several hours. For comparative purposes, a second solution of 4 parts of sodium sulfonate in 98 parts of the same white mineral oil was also prepared.

Separate steel panels were coated respectively with the solutions described above and allowed to drain for 2 hours at ordinary room temperatures. The coated panels were then partially immersed in a covered beaker of water which was maintained at a temperature of 50 C. Thereafter durv ing the test a stream of moist warm air was circulated through the system over the surfaces and the following results were obtained at the time indicated:

Oil-Buiionate-Resin Oil-sulfonate Unaffected. Do.

Very slight rusting.

.. Considerable rusting.

Example 2 The experiment described above in connection with Example 1 was repeated with the same compositions except that the water in the beaker was maintained at a temperature of 75 C. a It will be noted that this test was considerably more severe than that described in the foregoing example.

Time in Hours Oil-Sulfonste-Resin Oil-sulfonate 24 Unafl'ected Blight rusting at intersee.

48 do. Busting throughout.

96 Veryslightrustingat Serious rusting interface. throughout.

. pounds although use with the latter is preferred.

In general, the polymers which are useful in the present invention to improve adhesion of the rust preventive to the metal to be protected may be prepared by mixing together a substantial amount, preferably a major proportion of a multis olefin, having 4 to 14 carbon atoms per molecule,

and a suitable monoolefin of 8 to 20 carbon atoms, cooling the mixture to a temperature between C. and 103' C. and copolymerizing by introducing a suitable Friedel-Crafts catalyst.

The preferred diolefin is butadiene and the preferred monoolefln is the dimer of isobutylene or the so-called octene. While the precise manner of producing the polymer is not involved in the present invention, a suitable method is as follows:

The monoolefln and multiolefln are mixed in proportions of at least 85% of the multioleiin, e. g. butadiene, preferably at least 50% being used. This mixture is cooled to a temperature below 0' C. and not lower than 103 C. Cooling may be accomplished either by a refrigerating jacket about the reaction vessel, or by direct addition of a suitable refrigerant, such as propane, butane, methyl chloride, or the like. The mixture may I also contain an inert diluent such as butane, ethane, pentane, ethyl chloride, or other moderately low-boiling saturated hydrocarbons or substituted hydrocarbons. In some cases the refrigerant may serve also as a diluent.

Polymerization is conducted by the application to the refrigerated mixture of olefin and dioleiln (or polyolefin) of a suitable Friedel-Crafts catalyst, preferably in solution in a low-freezing noncomplex forming solvent. The catalyst preferred is aluminum chloride and the preferred solvent is ethyl or methyl chloride or carbon disulfide. However other catalysts and solvents may be used, such as aluminum chloro-bromide or aluminum ethoxide, or boron trifiuoride in the lighter saturated hydrocarbons such as butane, pentane, hexane, and the like. The resulting polymers have viscosity index improving properties, but their properties'of tackiness and of improving the adhesion of oils which contain them to metal surfaces, and of improving generally the rust-proofing properties of compositions of mineral oil containing oil soluble sulfonates, are of particular advantage in the present invention. The polymers preferably have a molecular weight of at least 1,000 to 15,000 or more, those with a molecso ular weight of 3,000 to 5,000 being especially preferred for use in rust inhibiting compositions.

The molecular weight may be controlled by controlling the proportions of the polymerizable ingredients, controlling the temperature, and/or 55 controlling the quantity and rate of addition of the catalyst, as wil be understood by those skilled in the art of preparing polymers and copolymers.

I claim: 1. A rust preventing composition consisting d0 essentially 01"80 to 98 parts of mineral oil, 0.1 to

parts of an oil soluble petroleum metal sulfonate, and 0.5 to parts of a copolymer of butadiene and diisobutylene, having a molecular weight between 3,000 and 5,000.

66 2. A rust preventing composition consisting essentially of 80 to 98 parts of an oil of petroleum base and lubricating grade, 0.1 to 10 parts of an oil soluble metal petroleum sulfonate, and 0.5 to 15 parts of a copolymer of 55 parts butadiene and 70 45 parts diisobutylene having a molecular weight between 1,000 and 15,000.

3.-A rust preventing. composition consisting essentially of 80 to 98 parts by weight of mineral oil, 0.1 to 10 parts of 011 soluble metal sulfonate. 7 0.5 to 15 parts of acopolymer of butadiene and 5 6 ilssogggfzlene of molecular weight between 1,000 and REFERENCES CITED 4. A rust preventing composition consisting The following references are of record in the essentially of 90 parts of mineral oil of lubricatfile of this patent:

ing grade, 4 parts of Oil Soluble petroleum Su1fO- P nate, and 6 parts of a resinous copolymer of 55 parts butadiene and 45 parts diisobutylene, said Number m Date copolymer having a molecular weight between ,127 h m s et 1 Aug. 22, 1 4

3,000 and 5,000. 2,382,699 Duncan Aug. 14, 194

5. Composition as in claim 3 wherein said sulfo- 10 nate is sodiumsulfonate.

JOHN D. GARBER. 

